A semiconductor such as a computer (central processing unit: CPU), a transistor and a light emitting diode (LED) generates heat during use thereof, and performance of such an electronic component decreases owing to the heat in some case. Therefore, in usual, a radiator is mounted on such an electronic component that generates heat.
Heretofore, for such a radiator as described above, metal having high thermal conductivity has been used. Note that, in recent years, an insulating thermally conductive resin composition, which has a high degree of freedom in shape selection and is easy to reduce weight and miniaturize, has been going to be used. For the purpose of enhancing the thermal conductivity, the insulating thermally conductive resin composition as described above must contain a large amount of a thermally conductive inorganic filler in a binder resin. However, it is known that a variety of problems occur if a blending amount of the thermally conductive inorganic filler is simply increased. For example, by increasing the blending amount of the thermally conductive inorganic filler, viscosity of the resin composition that is not still cured is increased, and moldability and workability thereof decrease to a large extent, causing a molding failure. Moreover, an amount of such a fillable inorganic filler has a limit, and accordingly, in many cases, the resin composition to be thus obtained does not have sufficient thermal conductivity (for example, refer to Patent Literatures 1 to 5).
Accordingly, there is disclosed a method for enhancing the thermal conductivity in such a manner that a bicontinuous phase-separated structure is formed by using a plurality of resins, and a thermally conductive filler is unevenly distributed on one of resin phases or a resin interface to thereby form a thermal conduction path (for example, refer to Patent Literatures 6 and 7).